Our Providers
Bedford, Berlin, Londonderry, Raymond, and Windham.
Gastroenterologists
Deepshikha N. Chowdhury, M.D.
Dr. Chowdhury is a graduate of Mount Sinai School of Medicine, St. Joseph’s University Hospital, NJ, and New York Medical College at St. Joseph’s University Hospital, NJ. She has a special interest in colorectal cancer screening, gastrointestinal cancers, biliary disease and inflammatory bowel disease.
Christopher N. Dainiak, M.D.
Dr. Dainiak is a graduate of Wesleyan University and the University of Connecticut Medical School. He performed his Internal Medicine residency at Yale University and Fellowship in Gastroenterology at the Norwalk/Yale program.
Laura C. Horton, M.D.
Dr. Horton is a graduate of Harvard College and Tufts University School of Medicine, where she was inducted into the Alpha Omega Alpha Honor Medical Society and received the Glasgow-Rubin Memorial Achievement Award from the American Medical Women’s Association as a woman graduating first in her medical school class.
Leon P. McLean, M.D., Ph.D., M.P.H.
Dr. McLean is board certified in Gastroenterology and in Internal Medicine. He is a graduate of Tufts University School of Medicine, where he earned his M.D. and Master of Public Health degrees, and of the University of Maryland, Baltimore, where he earned a Ph.D. in Molecular Medicine. He completed both his Internal Medicine residency and Gastroenterology fellowship at the University of Maryland School of Medicine and the Baltimore VA Medical Center.
Annette Tobar, M.D.
Dr. Tobar is a graduate of Tufts University School of Medicine and Tufts Graduate School of Biomedical Sciences where she earned her medical degree and master’s degree in clinical research. She completed her Internal Medicine residency at St Elizabeth’s Medical Center and Gastroenterology Fellowship at the University of Colorado in Denver.
Dr. Tsistrakis received his medical degree from Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, PA. He finished his residency at the Icahn School of Medicine at Mount Sinai Beth Israel in New York City. He did his Gastroenterology Fellowship at New York Presbyterian.
Advanced Practice Providers
Allison Anastasoff, APRN
Allison Anastasoff completed her Bachelor of Science in Nursing at Saint Anselm College in 2007. She earned her Master of Science in Nursing at the University of NH in 2016.
Alyssa Dunn, P.A.-C
Alyssa graduated from Saint Joseph’s College of Maine with a degree in Biology in 2011. She earned her Master’s degree in Physician Assistant Studies in 2015 from Massachusetts College of Pharmacy and the Health Sciences.
Stephanie Lynch, P.A.-C
Stephanie graduated from the University of Delaware with honors in 2011 with a degree in Biological Sciences. She earned her Master’s degree in Physician Assistant Studies with honors in 2015 from the Massachusetts College of Pharmacy and Health Sciences.